﻿#include"Date.h"

Date::Date(int year, int month, int day)
{
	if (month > 0 && month <= 12 && day > 0 && day <= GetMonthDays(year, month))
	{
		_year = year;
		_month = month;
		_day = day;
	}
	else
	{
		cout << "Ƿ" << endl;
		assert(false);
	}

}

bool Date::operator<(const Date& d)const
{
	if (_year < d._year)
	{
		return true;
	}
	else if (_year == d._year && _month < d._month)
	{
		return true;
	}
	else if (_year == d._year && _month == d._month && _day < d._day)
	{
		return true;
	}

	return false;
}

bool Date::operator==(const Date& d)const
{
	return _year == d._year && _month == d._month && _day == d._day;
}



bool Date::operator<=(const Date& d)const
{
	return *this < d || *this == d;
}

bool Date::operator>(const Date& d)const
{
	return !(*this <= d);
}

bool Date::operator>=(const Date& d)const
{
	return !(*this < d);
}

bool Date::operator!=(const Date& d)const
{
	return !(*this == d);
}

int Date::GetMonthDays(int year, int month)
{
	int daysArr[13] = { 0,31,28,31,30,31,30,31,31,30,31,30,31 };
	if (month == 2 && (year % 4 == 0 && year % 100 != 0) || (year % 400 == 0))
	{
		return 29;
	}
	else
	{
		return daysArr[month];
	}
}

Date& Date::operator+=(int day)
{
	if (day < 0)
	{
		return *this -= -day;
	}

	_day += day;
	while (_day > GetMonthDays(_year, _month))
	{
		_day -= GetMonthDays(_year, _month);
		_month++;
		if (_month > 12)
		{
			_year++;
			_month = 1;
		}
	}

	return *this;

	/**this = *this + day;
	return *this;*/
}

Date Date::operator+(int day)const
{
	Date tmp(*this);
	tmp += day;

	return tmp;

	/*tmp._day += day;

	while (tmp._day > GetMonthDays(_year, _month))
	{
		tmp._day -= GetMonthDays(_year, _month);
		tmp._month++;
		if (tmp._month > 12)
		{
			tmp._year++;
			tmp._month = 1;
		}
	}

	return tmp;*/
}


Date& Date::operator++()
{
	*this += 1;
	return *this;
}

Date Date::operator++(int)
{
	Date tmp(*this);
	*this += 1;
	return tmp;
}

Date& Date::operator-=(int day)
{
	if (day < 0)
	{
		return *this += -day;
	}

	_day -= day;
	while (_day <= 0)
	{
		--_month;
		if (_month == 0)
		{
			--_year;
			_month = 12;
		}

		_day += GetMonthDays(_year, _month);
	}

	return *this;
}

Date Date::operator-(int day)const
{
	Date tmp(*this);

	tmp -= day;
	return tmp;
}

Date& Date::operator--()
{
	*this -= 1;
	return *this;
}

Date Date::operator--(int)
{
	Date tmp(*this);
	*this -= 1;
	return tmp;
}

int Date::operator-(const Date& d)const
{
	Date Max = *this;
	Date Min = d;
	int flag = 1;

	if (Max < d)
	{
		Max = d;
		Min = *this;
		flag = -1;
	}

	int days = 0;
	while (Max != Min)
	{
		++Min;
		++days;
	}

	return days * flag;
}

ostream& operator<<(ostream& out, const Date& d)
{
	out << d._year << "-" << d._month << "-" << d._day << endl;
	return out;
}

istream& operator>>(istream& in, Date& d)
{
	int year, month, day;
	in >> year >> month >> day;
	if (month > 0 && month <= 12 && day > 0 && day <= Date::GetMonthDays(year, month))
	{
		d._year = year;
		d._month = month;
		d._day = day;
	}
	else
	{
		cout << "Ƿ" << endl;
		assert(false);
	}

	return in;
}